Material handling system

ABSTRACT

A fork lift truck, in preferred form, has a base frame, a rack frame, a mast, and an operator&#39;&#39;s platform. There is no center section at the bottom of the vehicle. The assembly is held together at the top with an arch formed by the mast and the truck rack frame. Two tie bars, one on each side on the vehicle, tie the frame together near the bottom. The tie bars are adjustable for height. A rigid mast supports an assembly which includes a carriage having a pivot-and-slide mechanism and a reach mechanism on which the fork is mounted. The pivot-and-slide mechanism permits the reach mechanism and its fork to be rotated and to be slidingly moved transversely from one side to the other. Thus, the mechanism permits the forks to deposit or to withdraw a load in both forward and side positions. An operator&#39;&#39;s platform is mounted on the truck forward of the mast.

in] 3,841,503 1 Get. 15, 1974 MATERIAL HANDLING SYSTEM [75] Inventor:Edwin A. Hollenbach, Paoli, Pa.

[73] Assignee: Drexei Industries, Inc., Horsham,

221 Filed: Mar. 7, 1973 211 Appl, No.: 338,919

Related US. Application Data [62] Division of Scr. No. 160,600, July 8,1971, Pat. No.

[52] US. Cl. 214/75 R, 214/16.4 R, 214/730 [51] Int. Cl 1360p l/44 [58]Field of Search 214/164 R, 75 R, 75 H,

[56] References Cited UNITED STATES PATENTS 2,197,375 4/1940 Dafnis214/392 2,576,345 11/1951 Jacob 214/392 3,190,473 6/1965 Loef 214/7303,521,779 7/1970 Warren et a1 .1 214/730 Primary ExaminerRobert J. SparAssistant ExaminerLawrence J. Oresky Attorney, Agent, or Firm-Paul &Paul [57] ABSTRACT A fork lift truck, in preferred form, has a baseframe, a rack frame, a mast, and an operators platform. There is nocenter section at the bottom of the vehicle. The assembly is heldtogether at the top with an arch formed by the mast and the truck rackframe. Two tie bars, one on each side on the vehicle, tie the frametogether near the bottom. The tie bars are adjustable for height. Arigid mast supports an assembly which includes a carriage having apivot-and-slide mechanism and a reach mechanism on which the fork ismounted. The pivot-and-slide mechanism permits the reach mechanism andits fork to be rotated and to be slidingly moved transversely from oneside to the other. Thus, the mechanism permits the forks to deposit orto withdraw a load in both forward and side positions. An operatorsplatform is mounted on the truck forward of the mast.

1 Claim, 6 Drawing Figures PATENTEU I 51914 3.841.503 sum 2 or 4MATERIAL HANDLING SYSTEM CROSS REFERENCE TO RELATED APPLICATION Thisapplication is a division of application Ser. No. 160,600 filed July 8,I971, entitled Material Handling System, now US. Pat. No. 3,727,778,granted Apr. 17, 1973.

BACKGROUND OF THE INVENTION This invention relates to material handlingvehicles and systems, and particularly to fork lift trucks and fork lifttruck systems.

It is, of course, well known to use fork lift trucks for stackingpalletized loads. However, prior art fork-lift material-handling truckshave not been sufficiently flexible, and a good deal of time is lost inunnecessary travel and motions.

SUMMARY OF THE INVENTION An important object of the present invention isto provide a fork-lift material-handling system in which one fork liftvehicle does the work of up to five prior art vehicles.

Another object is to provide a fork-lift materialhandling system inwhich the travel time of the fork lift vehicle is greatly reduced incomparison with prior art fork-lift material-handling systems.

A further object is to provide a fork-lift materialhandling systemcapable of handling loads stacked two deep in floor racks on each sideof the aisle.

Another object is to provide a material-handling system havingflow-through characteristics, with material being received at one endand shipped out at the other end.

A more specific object is to provide a fork lift truck having a truckrack on which the palletized loads are carried, and wherein any palletmay be randomly selected.

A broad object is to provide a material handling system havingflow-through characteristics which is applicable to both fork lift floorvehicles and overhead-rail crane stackers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of oneform of fork lift vehicle embodying the present invention.

FIG. 2 is a diagramatic plan view to illustrate how the fork lift truckof the present invention may be employed to carry out its purposes.

FIG. 3 is an elevation view, partly broken and partly in section,illustrating a modified version of fork lift vehicle according to thepresent invention.

FIG. 4 is a view looking along the line 4-4 of FIG. 3.

FIG. 5 is a view looking along the line 5-5 of FIG. 3.

FIG. 6 is a side elevational view of a presently preferred form of forklift vehicle in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is aperspective view of a fork lift vehicle embodying one form of thepresent invention. FIG. 6 is a side elevational view of a presentlypreferred form of fork lift vehicle embodying the present invention. Theprincipal difference between the vehicles shown in FIGS. 1 and 6 is thatin the vehicle of FIG. 6 the truck chassis has no center section. Thevehicle of FIG. 6 is tied together at the top by an arch formed by thetop of the mast 30 and the top of the truck rack 50. The lower portionof the truck is tied together at the center by a pair of tie bars 70,one on each side of the chassis. The tie bars 70 are adjustablevertically as to position. In other respects, the vehicle of FIG. 6 issimilar to that shown in FIG. 1. The vehicle of FIG. 1 will first bedescribed.

The vehicle shown in FIG. 1 includes a chassis 10 having at one end,arbitrarily designated the front end, a pair of front wheels 11 and atthe other or rear end a pair of rear wheels 12. At least one of thepairs of wheels is ordinarily steerable. An operators control position20, evidenced in FIG. 1 by the steering wheel 21, is provided at therearward end of the chassis. The vehicle is provided with known forms ofpower drive and control mechanisms for driving and controlling thevehicle and for operating the fork lift assembly.

At the forward end of the chassis 10 there is provided, in accordancewith the present invention, a rack in the form of a columnar structureor tower 50. Rack tower 50 contains a plurality of individualmaterialreceiving compartments arranged one above the other. In FIG. 1,six such individual compartments are shown, identified by referencenumerals 51 through 56, wherein 51 is the bottom-most compartment and 56is the upper-most. Each of the compartments 5l-56 is provided with apair of angle support members 57, one at each side of the compartments.These angle members 57 function as side rails for supporting the pallets58 bearing the loads 59. Windows 60 may be provided in the side walls ofthe rack tower 50 to facilitate identification of the palletized loadsin the compartments.

Immediately in front of the operators control position 20, and spacedrearwardly from the rack tower 50, is a mast lift assembly 30. The mastlift assembly includes, among other things, a pair of stationaryvertical guide channels or rails 31, movable guides 32 which areslidable up anddown in the stationary vertical guide channels 31, and acarrier frame 33 which is movable up and down relative to both the guiderails 31 and the guides 32. The carrier frame 33 carries the lift fork34. A pair of chains 35 are shown trained over a pair of pulleys 38carried at the upper end of a piston 36 of a hydraulic lift cylinder 37.One end of the chains 35 is fixed to the carrier frame 33 while theother end is fixed to the stationary guide rails 31. Thus, when thepiston 36 is extended, the carrier frame 33 is lifted through a distanceequal to twice that of the distance through which the piston 36 ismoved. The mast lift assembly 30 used in the vehicle of the presentinvention may be a well known form of mast lift assembly, and need notbe further described.

The fork 34 is supported on a scissor-like extension or reach mechanism40 which in turn is supported on a transverse carriage 41 which issupported on the elevatable carrier 33. Carriage 41 is movable back andforth transversely on the elevatable carrier 33. The extension or reachmechanism 40 is pivotably mounted on the transversely movable carriage4, and is pivotable through Thus, the fork 34 may be directed laterallyin either one of the two side directions, i.e., either toward the leftor toward the right side of the chassis.

Or, the fork 34 may be directed forwardly toward the rack tower S0. Thepivotally mounted scissors-like extension or reach mechanism 40 used inthe fork lift vehicle of the present application is known in the art andneednot be described in detail. Suitable reach mechanisms may, forexample, be obtained from The Raymond Corporation, Greene, New York, orfrom Long Reach Manufacturing, a division of Anderson-Clayton Company(Inc.), Houston, Texas, or from Cascade Corporation, Portland, Oregon,or from others.

The vehicle shown in FIG. 6 is generally similar to that of FIG. 1except that there is no center section at the bottom of the vehicle. Thetruck assembly is held together at the top by means of an arch 130formed by the mast 30 and rack tower 50. Two tie bars 70, one on eachside of the vehicle, are located near the bottom, preferably at theheight or level of the first rack cross frame. The tie bars 70 areadjustable for height. This arrangement, as compared with the vehicleshown in FIG. 1, permits the carriage assembly and the forks 34 to reachthe floor on both sides of the vehicle and to handle loads which rest onthe floor.

Another modification is illustrated in FIG. 3. The truck of FIG. 3differs from these of FIGS. 1 and 6 primarily in that the truck of FIG.3 is not equipped with a scissors extension or reach mechanism 40, butis instead provided with a pull-together mechanism. Like the trucks ofFIGS. 1 and 6, the truck of FIG. 3 includes a transverse carriagemounted on an elevatable carrier 33. The fork 34 is mounted on thecarriage 41 to be pivotable through 180 so that the fork 34 may bedirected either to the right or to the left of the chassis or forwardlytoward the compartments in the rack tower 50.

When facing forwardly toward the rack tower 50, the load on the fork 34may be deposited in a selected compartment of the rack tower 50 (or aload may be removed from a compartment of the rack tower 50) bypulling-together the two ends of the truck chassis, i.e., by moving therack tower end of the truck closer to the mast assembly. The means fordoing this will now be described.

In the chassis of FIG. 3, the rack tower section of the truck isseparated from the mast assembly section except for a pair of connectingracks 71. The forward ends of the racks 71 are fixed to the rack towersection. The rearward ends of the racks are free to move relative to themast assembly section of the truck. The mast assembly section isprovided with a pair of fixed racks 75, one on each side of the vehiclelocated in the same vertical planes as the racks 7ll. Cylinders 76having pistons 77 carry at their forward ends gears 78 which are adaptedto engage the teeth of the racks 71 and 75. It will be seen from FIG. 3that, when the pistons 77, one on each side of the vehicle, areretracted, the gears 78 will be caused to move counterclockwise, asviewed in FIG. 3, thereby causing the rack tower section 50 and the mastassembly section 30 to move toward each other, thereby causing the fork34 to enter into one of the compartments of the rack tower 50. Since themodified form of the vehicle illustrated in FIG. 3 does not have anextensionscissors reach mechanism 40, the form of vehicle shown in FIG.3 is not capable of handling loads which are located two deep in thefloor stacks.

The modified truck in FIG. 3 is illustrated as having several featureswhich may also be applied to the fork lift trucks of FIGS. 1 and 6.Where the warehouse ceiling is high, the mast lift assembly 30 may be sotall as to make stabilization desirable. In such case, a track or rail81, illustrated in FIGS. 3 and 4, may be secured to the ceiling beams80, and the upper end of the mast assembly 30 may be provided withbearings 82 which ride along the rail 81 thereby providing the necessarystabilization of the tall mast assembly 30. In some cases, it may alsobe desirable to provide an equally high rack tower and to also providethe rack tower 50 with bearings for riding along the guide rail 81.

An alternate form of stabilization is illustrated in the vehicle of FIG.6 where the arches portion 130 at the top of the vehicle is providedwith side stabilization rollers for bearing against the floor racks. Thestabilization rollers are identified 185.

In some cases, in order to relieve the operator of the necessity ofsteering the truck up and down the aisles, the chassis of the truck maybe provided with side guide rollers 85 just above the floor level, suchas are illustrated in FIG. 5 of the drawing. These side guide rollers 85may engage rails 86 which may be provided along the sides of the aislesat the floor level.

OPERATION The fork lift vehicle provided by the present invention, apreferred form of which is illustrated in FIG. 6, and other forms ofwhich are illustrated in FIGS. 1 and 3, enables the material to behandled on a flow-through basis, with receiving at one end and shippingor delivery at the other end. This system will now be described withreference to FIG. 2. FIG. 2 illustrates a fragment of a floor plan of awarehouse. Three stacking areas are shown identified as A, B and C. Eachof the areas is assumed to consist of four rows of palletized loads. Theoutside row of each area borders along a narrow aisle. The aisles areidentified as a, b, c and a. As seen, the aisles extend from a receivingarea, identified by the letter R, to a shipping or delivery area,identified by the letter D. The product may be received and handled by astandard truck in area R. Sorting into a feed rack may be provided atthe end of each aisle. Such feed racks may be capable of holdingvertically the same number of pallets as the rack of the fork lift truckis capable of handling, so as to match positions with the truck racks.The feed truck is driven up to the truck rack of the fork lift truck,and the truck racks are loaded, either by power or gravity feed. Thispermits simultaneous loading of all levels of the truck rack.

The fork-lift truck is driven down an aisle from left to right, asviewed in FIG. 2. En route, it may deposit and/or pick up palletizedloads in a variety of se quences. For example, assume that all six ofthe compartments 51-56 of the vehicle rack are filled with palletizedloads at the beginning of its travel from area R. This should be thecase if no load is to be picked up from the floor stacks before a loadis to be deposited. If, on the other hand, a palletized load is to bepicked up from the floor stacks before a palletized load on the truck isdeposited, the truck should, of course, have a vacant compartment in itsrack at the beginning of its run. In general, the number of vacantcompartments in the truck rack at the beginning of a run shouldcorrespond to the number of floor-stack loads which are to be picked upen route to the drlivery area D which exceed the number of palletizedloads which are to be deposited before reaching the delivery area D.

In FIG. 2, a truck TI is shown entering aisle b. A second truck T2 isshown in aisle c picking up (or depositing) a two-deep" palletized loadin the second row of area C. The palletized load which had been in thefirst row of area C has been picked up and deposited temporarily in oneof the rack compartments of the rack tower 50 of the truck T2. After thetwo-deep load is picked up from (or deposited in) the second row of areaC, the palletized load which had been in the first row will be returnedfrom the truck T2 to its position either in the first row or in the nowvacant spot in the second row. In FIG. 2, a third truck T3 is shown inaisle d depositing a load in (or picking up a load from) the fourth rowof area C. It is believed that from the description and explanationgiven thus far, the versatility of the operation which is available willbe apparent.

To summarize, in the system proposed by the present invention, using afork lift truck of the type or types shown in the present application,any pallet may be randomly selected on the truck rack 50. The reachmechanism 40 will extend forward and the fork 34 will lift the palletfrom the rack 50. The load is then withdrawn from the rack by closingthe reach mechanism. The loaded fork is then rotated to either one sideor the other, as selected. The loaded fork is then slidingly transferredto the side on the transverse carriage 33. This permits unloading (orloading) in the front or one-deep position of the floor rack. If thetwodeep or second position in the floor rack is involved, the reachmechanism 40 is extended and the load placed at (or picked up from) thesecond depth. The motion is reversed to withdraw a load from the floorracks.

Whenever a load has been removed from the truck rack 50, the space madeavailable in the truck rack may now receive a load from the floor rackfor delivery at the shipping or delivery end D. If two spaces are keptopen on the truck rack 50, a one-deep or front load from the floor rackmay be stored in the one open space, and the two-deep" or second loadfrom the floor stack may now be withdrawn and placed in the second opencompartment in the truck rack 50. The first or original load may then bereturned to the second position in the floor rack, and the second loadon the truck may be delivered to the shipping or delivery area D.

It will be seen that the equipment shown and described permits effectivehandling of loads which are two deep in the floor aisle, withoutexcessive traveling back and forth on the part of the truck. Long,narrow aisles (up to 600 feet) now become feasible because multipleloads can be handled without doubling back and forth or passing othertrucks in the aisles. The material-handling system described eliminatesapproximately two-thirds of the travel time presently used by fork liftvehicles for placing and withdrawing loads using conventional prior artfork lift equipment.

In the proposed system, one vehicle and its driver may replace up tofive prior art vehicles and their drivers. Thus, both equipment andmanpower are saved. The reduced travel time permits one operator to dothe work of up to five operators in about the same time. The fact thatloads stored two deep in the floor aisles may now be handled efficientlypermits savings on total rack space requirements. No passing of trucksin the narrow aisles is required under the presently described proposedmethod. Moreover, with the vehicle shown in FIG. 6, loads can be handledfrom the floor all the way to the top of the rack.

Stability of the truck, both longitudinally and transversely, may bemaintained by either over-head guides or roller stabilizers at the floorlevel or at the top of the assembly.

It is to be noted that the material handling system proposed inthe'present application is applicable to crane stackers as well as tofork lift trucks, since it is immaterial whether the vehicle besupported by wheels which ride on the floor of the warehouse or onoverhead rails.

In the claims which follow the term fork lift vehicle is intended toinclude elevatable fork vehicles which are supported on overhead railsas well as elevatable fork vehicles which are supported on the floor.

What is claimed is:

l. A material handling fork lift vehicle for handling palletized loadsin a room having a ceiling, said vehicle comprising:

a. a divided wheeled chassis having a forward section and a rearwardsection spaced apart from each other;

b. a high-rise rack tower on said forward section of said chassis;

c. said rack tower including a plurality of greater than three receivingcompartments arranged vertically one above the other;

d. a high-rise mast of fixed height secured in fixed position on saidrearward section of said chassis and spaced rearwardly from said racktower;

e. the upper end portion of said mast being connected by a horizontalbridge portion to the upper end of said rack tower, whereby said racktower, mast and bridge portion form an arch-like structure having athrough opening from the bridge portion down to the surface on whichsaid wheeled chassis is supported;

f. two horizontally disposed tie bars, each connected between one sideof said mast and the corresponding side of said rack tower, each tie barbeing vertically adjustable to provide structural support to saidarch-like structure at any selected vertical level;

g. roller means at said bridge portion adapted to cooperate with guiderail means supported from the ceiling to provide lateral support forsaid high-rise rack tower and mast;

h. a carriage arranged for vertical guided movement along said mast,said carriage including an operator station which projects outside ofsaid mast from that side of said mast which is opposite said rack tower;

i. hydraulic cylinder means for raising and lowering said carriage;

j. an overhead protective guard for said operator station and movabletherewith;

k. a fork lift assembly supported on said mast and having forksprojecting therefrom;

I. said fork lift assembly including pivot means for pivoting said forkthrough to direct said fork toward either side of said chassis or towardsaid rack tower;

m. said pivot means being mounted on said carriage and positionedbetween said mast and said rack tower;

8 said arch-like structured chassis allowing said fork to engage a loadon either side of said chassis at the level of the supporting surfacefor said wheeled chassis.

1. A material handling fork lift vehicle for handling palletized loadsin a room having a ceiling, said vehicle comprising: a. a dividedwheeled chassis having a forward section and a rearward section spacedapart from each other; b. a high-rise rack tower on said forward sectionof said chassis; c. said rack tower including a plurality of greaterthan three receiving compartments arranged vertically one above theother; d. a high-rise mast of fixed height secured in fixed position onsaid rearward section of said chassis and spaced rearwardly from saidrack tower; e. the upper end portion of said mast being connected by ahorizontal bridge portion to the upper end of saiD rack tower, wherebysaid rack tower, mast and bridge portion form an archlike structurehaving a through opening from the bridge portion down to the surface onwhich said wheeled chassis is supported; f. two horizontally disposedtie bars, each connected between one side of said mast and thecorresponding side of said rack tower, each tie bar being verticallyadjustable to provide structural support to said arch-like structure atany selected vertical level; g. roller means at said bridge portionadapted to cooperate with guide rail means supported from the ceiling toprovide lateral support for said high-rise rack tower and mast; h. acarriage arranged for vertical guided movement along said mast, saidcarriage including an operator station which projects outside of saidmast from that side of said mast which is opposite said rack tower; i.hydraulic cylinder means for raising and lowering said carriage; j. anoverhead protective guard for said operator station and movabletherewith; k. a fork lift assembly supported on said mast and havingforks projecting therefrom; l. said fork lift assembly including pivotmeans for pivoting said fork through 180* to direct said fork towardeither side of said chassis or toward said rack tower; m. said pivotmeans being mounted on said carriage and positioned between said mastand said rack tower; n. said fork lift assembly also includingscissors-like extension and retraction means for moving said fork intoand out of any selected one of said rack tower compartments and formoving said fork laterally outwardly to either side of said chassisthrough said opening in said arch-like structure, said arch-likestructured chassis allowing said fork to engage a load on either side ofsaid chassis at the level of the supporting surface for said wheeledchassis.